Methods of applying a fumigant to reduce fusarium contamination

Abstract

Described are methods of applying a fumigant to soil (e.g., in a field into which a Musa plant is to be planted) to reduce Fusarium contamination in the soil, such as Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4) (a.k.a. Fusarium odoratissimum). Methods to reduce Fusarium in soil in which Musa plants will be grown are described, including introducing a Fusarium—inhibiting effective amount of a composition including methyl isothiocyanate (MITC) or a compound that generates MITC, or a functional equivalent or alternative thereof, at least 40 cm below the soil surface; allowing it to release MITC in the soil; and allowing the MITC to reduce viable propagule count in the soil. Introducing the composition may involve applying it to soil at least 40 cm below the soil surface, and/or applying it to soil and mixing/blending the soil to a depth of at least 60 cm below the soil surface to distribute the composition.

1 . A method of delaying infection onset by  Fusarium oxysporum  f. sp.  cubense  Tropical Race 4 (Foc TR4) in  Musa  plants grown in soil, the method comprising:
 applying to the soil in which the  Musa  plants are to be grown a composition comprising methyl isothiocyanate (MITC) or a compound that produces MITC as a degradate (or a functional equivalent or alternative thereof), such composition being applied at a rate and in a manner which is effective for treating Foc TR4 to at least 60 cm below the soil surface;   waiting a sufficient period of time after applying the composition to the soil to permit the methyl isothiocyanate (MITC) (or functional equivalent or alternative thereof) to reduce viable Foc TR4 propagule count in the soil by at least 15% compared to the viable Foc TR4 propagule count in the soil before treatment; and   planting one or more  Musa  plants in the treated soil.   
     
     
         2 . (canceled) 
     
     
         3 . A method of reducing viable  Fusarium oxysporum  f. sp.  cubense  Tropical Race 4 (Foc TR4) in soil in which  Musa  plants will be grown, the method comprising:
 introducing an Foc TR4 inhibiting effective amount of composition comprising methyl isothiocyanate (MITC) or a compound that produces MITC as a degradate at least 40 cm below the surface of soil,   allowing the composition to convert to MITC; and   allowing the MITC to reduce viable Foc TR4 propagule count in the soil by at least 15% compared to the viable Foc TR4 propagule count in the soil before treatment.   
     
     
         4 . (canceled) 
     
     
         5 . A method of growing plants of the genus  Musa  in a field known or believed to be contaminated with  Fusarium oxysporum  f. sp.  cubense  Tropical Race 4 (Foc TR4), the method comprising at least two repetitions of a treatment and planting cycle comprising
 introducing to at least 40 cm below the surface of soil in the field an Foc TR4 inhibiting effective amount of a composition comprising methyl isothiocyanate (MITC) or a compound that produces MITC as a degradate (or a functional equivalent or alternative thereof),   allowing the MITC to reduce viable Foc TR4 propagule count in the soil, to produce treated soil;   planting plants of the genus  Musa  into the treated soil;   growing the plants of the genus  Musa  for a plurality of years;   harvesting fruit from at least one of the plants of the genus  Musa  each of the plurality of years; and   removing the plants of the genus  Musa  from the field.   
     
     
         6 . The method of  claim 5 , wherein the plurality of years in at least one repetition of the treatment and planting cycle comprises 3 years, 4 years, 5 years, 6 years, 7 years, 8 years, 9 years, 10 years, or 11-15 years. 
     
     
         7 . The method of  claim 5 , wherein introducing the composition to at least 40 cm below the surface of soil in the field comprises applying the composition to the soil:
 (I) at two depths between 0 cm and 60 cm below the soil surface, wherein a first depth is at least 40 cm below the soil surface and a second depth is 0 to less than 40 cm below the soil surface; or   (II) to produce treated soil; and mixing/blending the treated soil to a depth of at least 60 cm; or   (III) at two depths between 0 centimeter and 60 cm below the surface, wherein a first depth is at least 40 cm below the surface and a second depth is 0 to less than 40 cm below the surface; and blending the soil such the composition and/or degradate(s) derived therefrom is distributed throughout the soil to a depth of more than 40 cm.   
     
     
         8 . The method of  claim 1 , wherein the composition comprises:
 metam sodium, metam potassium, metam ammonium, or dazomet.   
     
     
         9 . The method of  claim 8 , wherein the metam sodium comprises:
 sodium N-methyldithiocarbamate; or   methyldithiocarbamic acid sodium salt.   
     
     
         10 . The method of  claim 8 , wherein the metam potassium comprises:
 potassium N-methyldithiocarbamate; or   methyldithiocarbamic acid potassium salt   
     
     
         11 . The method of  claim 1 , wherein the composition comprises:
 300-700 grams of methyldithiocarbamate equivalents per liter of solution;   
     
     
         12 . The method of  claim 1 , wherein the soil has a water holding capacity, and at the time of treatment, contains water at a level of:
 40%-80% of the water holding capacity of the soil;   
     
     
         13 . The method of  claim 1 , wherein the composition is applied to the soil at a rate of:
 500-5,000 liters per hectare.   
     
     
         14 . The method of  claim 1 , wherein at least one  Musa  plant is planted in the treated soil:
 at least 3 days after the treatment.   
     
     
         15 . The method of  claim 14 , wherein at least one  Musa  tree is a  Musa acuminata  banana plant or a plantain plant. 
     
     
         16 . The method of  claim 15 , wherein the  Musa acuminata  banana plant is a Cavendish triploid (AAA) cultivar banana plant. 
     
     
         17 . The method of  claim 15 , wherein the plantain plant is a Plantain triploid (AAB)  Musa acuminata  and  Musa balbisiana  hybrid plant. 
     
     
         18 . The method of  claim 1 , comprising one or more of:
 injection application of the composition to the soil using shank/chisel blade drawn by a tractor or other motorized machine;   injection application of the composition to the soil using a goose foot blade drawn by a tractor or other motorized machine;   mixing at least some of the soil to distribute the composition or a degradate thereof;   tilling the soil; or   disking the soil.